The present invention relates to devices for folding up and securing a container by a simplified means which includes a mandrel and a die opening which, when the blank for the container is placed appropriately over the die opening, cooperates so that the movement of the mandrel toward the blank and into the die opening causes the erection and completion of the container. The container preferably is of a type that has a flat bottom with front and rear walls extending therefrom and opposite each other and side walls extending therefrom at 90.degree. to the front and rear walls. All of the walls are tapered so that they increase in size toward the opening of the container from their juncture with the bottom wall to a wider open mouth.
The front and rear walls have side panels which may be glued to each other and to the side panels extending from the bottom wall in order to complete the container. The container itself thus becomes a tapered frusto-tetrahedron having a smaller bottom wall than the opposite opening. These containers may be nested.
The device of the present invention is so arranged that when the container is completed by having it forced through the die by the mandrel, the glue having been applied in appropriate places beforehand, the container will drop down on a moving belt which will tip the container so that its bottom end is directed in the direction of movement of the belt and the belt will then drive the container toward other containers which have been similarly directed and which have been halted by a stop bar so that the container will nest with the last of the previous containers producing a complete series of nested containers which may be removed as a group.
Most frequently, such containers are utilized by fast food outlets or stands in theaters for the purveying a product, such as popcorn, or other products which may readily be filled into such containers by using the container as a ladle itself or by other means of filling the container wherein it is possible that certain liquids, such as the butter added to popcorn, may leak. Hence, the side walls of the container above referred to and the side panels extending from the front and back walls are connected by triangular sections located between them which form triangular gussets which are folded in as the container is formed in order to provide an integral closure for the bottom wall and to prevent any leakage of any nature whatsoever.
The machine for erecting the container to which this invention is directed comprises a stack storing means for the blanks, the blanks being so arranged so that they are either delivered toward the bottom of the stack and held there by gravity or by any equivalent force. The bottom of the stack need not necessarily be parallel to the floor but is simply the end of the stack from which the successive blanks are taken. They may be at some angle to the floor and may even be horizontal as long as means are provided for exerting appropriate pressure on the stack to cause it to bear against a bottom support and with means provided for inserting additional blanks as the need arises.
The bottom of the stack is supported by a framework which engages outer portions of the lowermost blank in the stack to permit the blank to be withdrawn. Preferably, a vacuum pick-up for the bottom blank is provided rotating through approximately 90.degree. or more from the bottom of the stack to a position above the die opening through which the blank is forced to be formed. The blank is pulled off the bottom of the stack by the vacuum pull causing the edges of the blank to slip off the support and permitting the next blank to be engaged by the stack support. The vacuum support then rotates to a position where the blank is just above the die opening and the vacuum is released to permit the blank to drop appropriately oriented over the die opening.
The male mandrel which extends above the die opening at a distance above the die opening so that it will not interfere with the placement of the blank as the vacuum pick-up for the blank moves back toward the bottom of the stack for the next blank, moves down to force the blank through the die opening with appropriate compressing and guide means being provided along the sides of the die opening.
Prior to the engagement of the mandrel with the blank, a set of glue applicators on each side apply glue to the side panels of back wall of the blank on both sides in a manner herein specifically described. And also apply glue to the side walls. Then, as the glue applicator moves out of position with the vacuum pick-up moving back toward the next blank, the male mandrel comes down forcing the blank through the die. The pressure on the sides of the die helps to guide the blank firmly but resiliently but also exerts sufficient pressure to spread the glue and cause the glue to adhere to adjacent panel walls in order to complete the formation of the blank.
The blank is thereby folded up into substantially rectilinear condition with, however, all walls preferably flaring from the bottom wall and is dropped down, as above pointed out, on a conveyor which causes the blank to tip its bottom wall in the direction of movement of the conveyor, thereby moving the carton toward the stalled set of nested cartons for insertion into the topmost of the nested cartons. In this case, the nested cartons are lying on their side and the topmost end is extending substantially normally to the belt so that the carton which is formed is automatically inserted into this topmost nested carton.
As the length of nested cartons grows, the batch of cartons is removed. The stalling means may be any suitable bar or wall which will cause the box to stop while the belt moves with respect thereto.
The die itself, while it has a rectangular opening through which the blank is forced, is necessarily so arranged that it may control the blank and receive the blank as it is being formed into the frusto-tetrahedral shape which is narrower at the bottom and wider at the top. For this purpose, a pair of compression rolls are used at the portion of the die which forms the container so that the glue may be subject to appropriate pressure as the blank is being formed and forced therethrough, but, nevertheless, the blank may be completely controlled, first, as the narrow or bottom end enters and then as the wider and flaring upper portions pass through.
A pair of additional spring biased rolls may be provided in the die for the front and back walls so that the effective size of the die, as determined by the roll, will vary appropriately to fit both the blank as it is being formed and the mandrel.
Thus, as the mandrel comes down onto the blank and forces it through the die, the front and back walls of the die are folded up and then the side walls of the die are folded up, owing to the arrangement of the mandrel and the arrangement of the die, with the side walls being folded up on the outside of the front and back walls and being appropriately adhesively secured thereto.
Additional front and back wall rollers may be utilized, biased against the other two sides of the die in order to maintain complete control.
In the operation of the device, the blank, when first delivered to the die, is delivered on a support platform section, or trestle, somewhat above the die. The glue is applied when the blank is thus delivered and as the blank pick-up member moves out of the way toward the next blank to be picked up providing clearance for the mandrel as well. The glue having been applied and the blank pick-up being out of the way, the mandrel starts down.
The support for the blank may comprise relatively narrow support members defining essentially a support structure along the edges of the blank. In addition, folding guides are provided in connection with the support structure so that as the blank is forced down into the die, the folding guides which extend somewhat into the path of movement of the blank, but not so far as to interfere with the movement of the mandrel engage the triangular connection panels on each side between the side panels of the front and back wall and the side panels to direct them inwardly to form the bottom seal.